ASTM A387 Grade 91 Class 2 vs. Grey Cast Iron
Both ASTM A387 grade 91 class 2 and grey cast iron are iron alloys. They have 90% of their average alloy composition in common. There are 30 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.
For each property being compared, the top bar is ASTM A387 grade 91 class 2 and the bottom bar is grey cast iron.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 200 | |
| 160 to 300 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 180 |
| Elongation at Break, % | 20 | |
| 9.6 |
| Fatigue Strength, MPa | 330 | |
| 69 to 170 |
| Poisson's Ratio | 0.28 | |
| 0.29 |
| Shear Modulus, GPa | 75 | |
| 69 |
| Shear Strength, MPa | 420 | |
| 180 to 610 |
| Tensile Strength: Ultimate (UTS), MPa | 670 | |
| 160 to 450 |
| Tensile Strength: Yield (Proof), MPa | 470 | |
| 98 to 290 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 280 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1380 |
| Melting Onset (Solidus), °C | 1420 | |
| 1180 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 490 |
| Thermal Conductivity, W/m-K | 26 | |
| 46 |
| Thermal Expansion, µm/m-K | 13 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 8.9 | |
| 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 10 | |
| 8.9 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 7.0 | |
| 1.9 |
| Density, g/cm3 | 7.8 | |
| 7.5 |
| Embodied Carbon, kg CO2/kg material | 2.6 | |
| 1.5 |
| Embodied Energy, MJ/kg | 37 | |
| 21 |
| Embodied Water, L/kg | 88 | |
| 44 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 13 to 37 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 580 | |
| 27 to 240 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 24 | |
| 5.8 to 17 |
| Strength to Weight: Bending, points | 22 | |
| 8.7 to 17 |
| Thermal Diffusivity, mm2/s | 6.9 | |
| 13 |
| Thermal Shock Resistance, points | 19 | |
| 6.0 to 17 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.020 | |
| 0 |
| Carbon (C), % | 0.080 to 0.12 | |
| 3.1 to 3.4 |
| Chromium (Cr), % | 8.0 to 9.5 | |
| 0 |
| Iron (Fe), % | 87.3 to 90.3 | |
| 92.1 to 93.9 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0.5 to 0.7 |
| Molybdenum (Mo), % | 0.85 to 1.1 | |
| 0 |
| Nickel (Ni), % | 0 to 0.4 | |
| 0 |
| Niobium (Nb), % | 0.060 to 0.1 | |
| 0 |
| Nitrogen (N), % | 0.030 to 0.070 | |
| 0 |
| Phosphorus (P), % | 0 to 0.020 | |
| 0 to 0.9 |
| Silicon (Si), % | 0.2 to 0.5 | |
| 2.5 to 2.8 |
| Sulfur (S), % | 0 to 0.010 | |
| 0 to 0.15 |
| Titanium (Ti), % | 0 to 0.010 | |
| 0 |
| Vanadium (V), % | 0.18 to 0.25 | |
| 0 |
| Zirconium (Zr), % | 0 to 0.010 | |
| 0 |